Use of a Rubber Hose as an Acoustically-Transparent Pressure Vessel for Testing Line Transducers,

摘要

This report presents theoretical and experimental results concerning the use of a rubber hose as an acoustically-transparent pressure vessel for testing underwater acoustic line transducers. Commercial, nylon-reinforced rubber hoses are available with a continuous hydrostatic pressure rating of 500 psi. Tests of an 'Empex' type B-183 hose indicate that the acoustic attenuation depends primarily on the hydrostatic pressure. At 500 psi the acoustic attenuation is about 2 dB, and between 500 psi and 200 psi the attenuation increases by less than 0.2 dB per 100 psi. The fluctuation of acoustic attenuation with frequency is less than 0.7 dB from 35 kHz to 100 kHz, and the change of acoustic attenuation due to nonuniformity of the hose wall is less than 0.5 dB. It is shown that for rotations about the acoustic axis, correct acoustic directivity patterns are obtainable for rotations up to a maximum angle from the acoustic axis; and an expression for calculating that angle is given. (Author)